The return value of smp_execute_task_sg() is the untransferred residual,
but bsg_job_done() requires the length of payload received. This makes
SMP passthrough commands from userland by sg ioctl to libsas get a wrong
response. The userland tools such as smp_utils failed becuase of these
wrong responses:
~#smp_discover /dev/bsg/expander-2\:13
response too short, len=0
~#smp_discover /dev/bsg/expander-2\:134
response too short, len=0
Fix this by passing the actual received length to bsg_job_done(). And if
smp_execute_task_sg() returns 0, this means received length is exactly
the buffer length.
Fixes: 651a01364994 ("scsi: scsi_transport_sas: switch to bsg-lib for SMP passthrough")
Reported-and-tested-by: chenqilin <chenqilin2@xxxxxxxxxx>
Signed-off-by: Jason Yan <yanaijie@xxxxxxxxxx>
CC: Christoph Hellwig <hch@xxxxxx>
---
drivers/scsi/libsas/sas_expander.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/drivers/scsi/libsas/sas_expander.c b/drivers/scsi/libsas/sas_expander.c
index 50cb0f3..6c40ecc 100644
--- a/drivers/scsi/libsas/sas_expander.c
+++ b/drivers/scsi/libsas/sas_expander.c
@@ -2143,7 +2143,7 @@ void sas_smp_handler(struct bsg_job *job, struct Scsi_Host *shost,
struct sas_rphy *rphy)
{
struct domain_device *dev;
- unsigned int reslen = 0;
+ unsigned int rcvlen = 0;
int ret = -EINVAL;
/* no rphy means no smp target support (ie aic94xx host) */
@@ -2177,12 +2177,12 @@ void sas_smp_handler(struct bsg_job *job, struct Scsi_Host *shost,
ret = smp_execute_task_sg(dev, job->request_payload.sg_list,
job->reply_payload.sg_list);
- if (ret > 0) {
- /* positive number is the untransferred residual */
- reslen = ret;
+ if (ret >= 0) {
+ /* bsg_job_done() requires the length received */
+ rcvlen = job->reply_payload.payload_len - ret;
ret = 0;
}
out:
- bsg_job_done(job, ret, reslen);
+ bsg_job_done(job, ret, rcvlen);
}
--
2.9.5
